Auto ISO is one of many helpful features that has become a core feature of digital cameras, and it’s something I’ve come to rely on a lot.
Back in film days, you were generally confined to the ISO of the roll of film that was loaded. Digital cameras, though, can have a different ISO for each shot. And better yet, it’s adjusted silently on the fly by the camera itself.
On the OM System OM-5, the Auto ISO feature works well out of the box with the default settings, but there are also some ways to tweak its behavior, such as limiting the maximum ISO it will use.
Here’s a rundown of the available options and how to use them.
Available Auto ISO settings on the OM System OM-5
You can find the settings for the Auto ISO feature under the gear icon.
Gear (cog) icon > E1 > ISO-Auto Set
Under that, you’ll find two further sets of options. The first is Upper Limit / Default. This sets two things about the Auto ISO.
Upper Limit
The Upper Limit refers to the ISO ceiling when using Auto ISO feature.
Or, put it another way, it’s the maximum ISO that Auto ISO will go to.
The default on the OM-5 is ISO 6400. But perhaps you might want to set it lower than that to make absolutely sure you don’t run into image noise because you’re working with a stock agency, for example (stock agencies are often very strict about image noise).
There is something important to know about this setting: ISO 6400 is both the default setting and also the maximum that you can be used with Auto ISO. That is, you can change it to lower than 6400, but you can’t set it higher.
There are some other setting combinations that affect the available maximum ISO here, such as if the live ND (neutral density) filter is enabled.
What that means is that you want to take advantage of the full ISO range of the OM-5, which goes all the way up to ISO 25600, you can’t do it while using the Auto ISO feature–you’ll need to set that ISO manually.
Default
The Default setting is the baseline ISO used. The default is ISO 200, which is a compromise of image quality and sensitivity speed that’s weighted toward image quality.
Using the default setting of 200 as an example, what it means is that it will first try to expose with an ISO of 200. But if the light and the combination of shutter speed and aperture won’t support that, then it will move up to the next closest ISO that will work. Or, put another way, it will favor ISO 200 for each shot and only deviate from that if there’s not enough light (in combination with the other parts of the exposure triangle, shutter speed and aperture).
An example of where you might want to set this higher is if you want to encourage the camera toward faster shutter speeds when using P or A shooting modes.
Lowest S/S setting
The lowest shutter speed option sets the threshold for shutter speed when making the calculation on exposure and Auto ISO. So it’s similar to the Default setting above but this time applies to shutter speed rather than ISO. But it still affects ISO because it’s all part of the symbiotic exposure triangle calculation.
Where this is most important is in setting a floor to minimize any effects of camera shake. The Auto setting will calculate the minimum shutter speed used in the calculation based on the focal length of the lens being used.1
But you can also override the Auto setting and assign a minimum shutter speed of 1/250sec. This can be especially effective when trying to freeze action or ensure that camera shake doesn’t become a problem.
ISO-Auto
The separate ISO-Auto setting adjust a related option, but it’s a simple one. It changes which shooting modes the Auto ISO feature is available in.
The default is in Program/Aperture Priority/Shutter Speed Priority/Manual modes.
But you can choose to leave Manual off that list. It’s a small tweak, but it’s one I like. That’s because when you shift to manual mode, there’s a good chance you’re aiming for something very deliberate. You might be wanting to create some motion blur, for instance, so you don’t want Auto ISO fighting against you. Another place I find it useful is if I’m shooting a sequence where I need identical exposure from shot to shot, such as shooting panels to be stitched for a panorama.
OM System OM-5 price & availability
The OM-5 body has an MSRP of $1200. It’s also sold with a 12-45mm f/4 PRO kit lens for $1600.
Check the current price and available at:
OM System OM-5 camera accessories
These are the model numbers for the official accessories for the OM System OM-5.
- Battery: BLS-50 lithium-ion rechargeable battery
- External Charger: BCS-5
- USB-AC Adapter: F-5AC AC wall adapter
- Grip: ECG-5
- Remote: RM-WR1 wireless remote control
- Eyecup: EP-16 / EP-15
- Flash:
Related
Notes & References:
- I haven’t tested for the precise ratio used on the OM-5, but on other cameras it’s typically around 1:1, which is based on the old photography rule of thumb of using a shutter speed that’s at least as fast as the focal length to minimize the effects of camera shake. So shooting with an effective focal length of 50mm, for instance, would allow for a minimum shutter speed for 1/50 of a second. And a telephoto lens focal length of 250mm would suggest a shutter speed of 1/250th of a second. (NB: It’s worth noting that this is for effective focal length. On a Micro Four Thirds camera, that means doubling what’s written on the lens. So a Micro Four Thirds focal length of 40mm is an effective focal length of 80mm.) But that rule of thumb doesn’t factor in image stabilization, so there might be a different ratio at work (or even several ratios) on the OM-5. [↩︎]
Thanks for the insights on how the auto ISO is working/limited.
You say that in manual exposure mode and using that to create motion blur, you set the ISO to manual, as you do not want that to fight against you when creating the motion blur.
When using manual exposure you set the exposure time and the f-stop to a fixed value. Please elaborate on how an automatic ISO should work against that?
Image stabililization is great in the OM-5, so the old rule of exposure time at least the focal length is good to have as a base, but stable handheld can be achieved with like 4 stops longer times with good result. In this case motion blur will be more of the problem depending on how much objects are in motion. I think you should try it.
Camera shake and motion blur are two different things. The image stabilization is aimed at camera shake.
Motion blur isn’t always a “problem” but can be deliberate: star trails, flowing waterfalls, car headlights on roads, removing people from photos, etc. And it’s often shot with tripods or on other secure mounts, rendering the image stabilization moot.
If you’re trying to set a long exposure to create motion blur and have Auto ISO on, the camera’s auto exposure calculation will adjust the ISO on the fly. And in the situations where I’m specifically trying to get motion blur, that often results in a high ISO, or at least higher than I want. With Auto ISO on, dropping down the ISO again means either changing the shutter speed or changing the aperture, which defeats the purpose of using manual. So I find I get far more consistent results more quickly by turning it off and going full manual and adjusting each setting–aperture, shutter speed, and ISO–directly rather than in some secondary way.